Which of the following is a sign of exercise-associated hyponatremia?

Exercise-associated hyponatremia (EAH) is a condition that occurs when there is an imbalance of sodium in the body, often as a result of excessive fluid intake during prolonged exercise. One of the common signs of this condition is a headache, which can result from the swelling of brain cells due to an electrolyte imbalance.

This symptom arises because the low sodium levels disrupt the normal osmotic balance and can lead to fluid shifting into cells, particularly in the brain. As this swelling occurs, it can result in increased intracranial pressure, leading to headaches as a key indicator of this condition.

Recognizing a headache in the context of prolonged physical activity, especially when coupled with rapid fluid replacement, is crucial for athletes and trainers to identify potential signs of EAH, allowing for timely intervention and prevention of more serious complications.